Dr. Schoenfeld: So, in my humble opinion, certainly every form of exercise or most forms of exercise are very beneficial. Doing something has always been better than doing nothing for your health. But if I were to pick one activity that is indispensable, it would be resistance training. And there's a couple of reasons. So, certainly cardiovascular exercise, it's been much more well researched over the years, and indisputably it has great effects on your health and wellness, but resistance training has many of the same benefits as cardiovascular exercise but it goes well beyond what you can get through aerobic training. And particularly dealing with muscle strength, obviously, and bone density and other things like posture.

So, aerobic exercise itself has very minimal effects on your strength levels, on muscle development, on muscle hypertrophy, even on bone development. So, certainly running has certain benefits to bone but nothing in the way that resistance training does. And again, things like your posture, people need to consider doing...if you are sedentary and not doing anything, over time, you're going to lose muscle, your posture is going to go. And you can do all the aerobic training you want, it's really not going to have these benefits.

Dr. Patrick: So, you just mentioned two things that I was unaware of, bone density and the posture, so, can you talk a little bit more about that, resistance training affecting bone density?

Dr. Schoenfeld: Yeah, sure.

Dr. Patrick: Because that seems very relevant for particularly post-menopausal women.

Dr. Schoenfeld: It is. So, osteoporosis, which is basically porous bones, it's when, over time, the aging process, your bones, if you are sedentary in particular, will start to degrade. And the 80% of people with osteoporosis are women because women generally, number one, start out with less bone mass and there's also effects of, as you mentioned, estrogen is osteoprotective. So, when women undergo menopause, postmenopausally, they're going to have increased bone resorption, which is going to increase their chances of getting osteoporosis.

And resistance training, by pulling on the bones, muscle pulling on the bones, so, there's an interaction, your musculoskeletal system is the muscle that allows, when you have movement, it's the muscle pulling on the bones to move. And strength training really is the primary way to strengthen the bones. So, while you're strengthening the muscles, necessarily the bones become strengthened as well. There's certain ways that are going to be more appropriate than others to maximize that process but really, no matter what type of resistance training you do, whether it's light loads, heavy loads, etc., you're going to be strengthening bones.

And it's always, by the way, specific to the joint that you're working. So, weight-bearing exercise in particular is what strengthens bones. If you're doing cycling or even the elliptical machine, it's really not weight-bearing enough to have substantial effects on bone development, and swimming and other endeavor. Whereas, running, to some extent, there is ground reaction forces but it's mostly specific to the femur, to your lower-body musculature, whereas the spine and the wrist is going to be a major area for osteoporosis, particularly in women. Anyway, long story short is that resistance training, when done regularly and consistently over time, has profound effects on staving off the potential for osteoporosis and even building bones, particularly when you're younger.

Dr. Patrick: You said there are certain types of exercises that may, you know, be better...or is there any types of exercises that you can talk about?

Dr. Schoenfeld: Yeah. So, most of the research has been using somewhat moderate to heavier load. I'm not convinced though, I think it's an effect that we just don't have research that's really looked at doing lighter-load training with bone density. And I would surmise, if you are training with a good deal of effort, high levels of intensity of effort, that you would achieve similar effects, but it also does seem that doing more multi-joint movements...so, multi-joint meaning like squats, movements that are utilizing more than one joint, multi-joint is more than one joint, so, rather than a curl, you can get better effects overall on bone because of the loading that is imposed. So, again, not really great evidence, this is more speculative, based upon the literature I've seen. So, again, I'm a fan of any type of resistance training over not but if you're looking to maximize bone development, I would certainly say you want to include some multi-joint movements. And I think, just in general, there's other reasons why you want to as well.

Dr. Patrick: Besides the squats, what are some other, like, body...

Dr. Schoenfeld: Rows, presses...I mean, push-ups, you know, any type of movement where you're involving more than one joint.

Dr. Patrick: For, like, someone that's working with dumbbells, for example, who's not going to go use a machine, can you do multi-joint movements without that?

Dr. Schoenfeld: Yeah, shoulder press, so, I mean, chest press. Dumbbells are great, sure. Shoulder press, chest press. You can do squats, you can do a goblet squat, where you hold the dumbbell here and do a squat. So, yeah.

Dr. Patrick: Well, that was very...I mean, I had a question there about bone density but I didn't realize that it really does play a significant role in the bone density, and it's really good to know about that. Muscle mass in general, aging. I mean, what about someone who hasn't...let's say, you know, they're more of an endurance athlete, like, throughout most of their, you know, young adulthood and they're getting into even just maybe perhaps older age? Is it ever too late to start resistance training to help, you know, build muscle mass or help prevent the atrophy that's going to happen?

Dr. Schoenfeld: Absolutely not. So, in my previous life, I was a personal trainer before becoming an educated researcher and, I mean, literally I was involved in the training of thousands of individuals. And I had clients at the time that were 60s, 70s, and 80s, never lifted a weight, and saw huge benefits in relatively short periods of time. We carried out a meta analysis on the oldest of old, which was 70 and above. Well, 70s actually not that...it's the new 50 now, 70. But 70-plus-years-old and up octogenarians, profound improvements in muscle strength, muscle hypertrophy within 12-week, 8 to 12-week training programs, these are novice trainees who've never done anything before.

Now, I will say this with the caveat, it's always better to start when you're young. The earlier you start, the better. Because, once you start losing, to get it back is harder. So, you can always improve upon where you're at at a given point in time but trying to get back to where you were when you're in your 20s is going to be almost impossible if you're not starting till you're 70. However, if you start when you're in your 20s, you can maintain a majority of your muscle mass. And certainly I would say this, someone who is not doing anything in their 20s, I've had clients in their 70s who were stronger and more fit than people in their 20s, who were, you know, serious lifters. So, yeah, it's always best to start when you're younger. And I will say this too, for women in particular and particularly in reference to bone density, it is very important to start early. Again, it's never too late because you can get some, to some extent...

Dr. Patrick: How early?

Dr. Schoenfeld: I mean, as early as you can but certainly like in your teens and twenties because you do build up a bone bank. I mean, the analogy I like to use is having a retirement account. Yeah, it's never too late to start, technically, but if you start in your 50s, your retirement is not going to be what it is if you start in your 20s. And there is this concept of a bone bank where, if you start when you're young, and particularly, again, for women, who have the biggest issue with osteoporosis, you end up staving off the possibility of having osteoporosis. If you start when you've already lost bone density, it's very difficult to get back. You know, you can stave off, you can certainly prevent the progression of osteoporosis, but getting back your bone density becomes much more difficult.

Dr. Patrick: So, it's very similar to this concept of building up a muscle reserve, right, where...because that's also, right, when you're...

Dr. Schoenfeld: Correct.

Dr. Patrick: ...in, I don't know, 30s even maybe, you start to lose the muscle mass. And so, yes, like you said, starting with that bigger reserve is always better because things are going to be taken away from it so you want to have, like, a bigger starting point. So, that's really great to know because, you know, in particular for women I think, you know, and at least for myself in particular, and I know, like, many of my friends and growing up even, you know, throughout high school, I mean, we were always endurance, we were endurance athletes. You walk into the gym and there was mostly guys in there lifting weights, you know, the wrestlers, the...you know, and so, I don't know, this may be changing now, where women are starting to understand the importance of resistance training and building up muscle mass and bone mass through resistance training but, you know, for me, it was always endurance. If I'm doing my endurance then I'm checking the box, you know, I'm getting that exercise, I'm going to be healthier because of it.

So, it's really so important I think for young women too to really...it's easier to convince young men who, like, want to get the muscle, I mean, for them, they've got other goals as well in mind, but I think there's now a growing interest in bone mass and bone density, preventing osteoporosis as well. So, that's really great to know. What about starting, like, so, starting young? Like, you know, can you start, like, in childhood?

Dr. Schoenfeld: Absolutely. So, there's compelling research now that children...kind of it's never too young to start, provided the child's maturity is such that they're able to lift. I will say that always it should be done, especially early on, if you're dealing with children six, seven, eight-years-old, you want to have a fully supervised environment. Even beyond that, until they are, you know, in their teens even. But yeah, there's really compelling research now that resistance training in youth not only is not detrimental...so, I mean, I want to dispel the myth now that it stunts growth. I mean, there's been this myth around forever that, you know, the training, if you do resistance training early on, it will stunt your growth. Zero evidence.

Dr. Patrick: I would think the opposite because growth hormone increases with resistance training...

Dr. Schoenfeld: Yeah, growth hormone really does not have the effects on, interestingly, even though the name is growth hormone, it's really not the driving force of development. Well, it is on height...

Dr. Patrick: Height, yeah, that's what I mean.

Dr. Schoenfeld: But growth hormone is pulsatile, and the effects on growth hormone for...it's actually interesting, it's never been studied, but it's pulsatile and the effects on growth hormone with resistance training are very specific to 1 hour or so after the workout. But it was thought that you would injure the epiphyseal plates and that would, you know, somehow stunt the growth. Anyway, zero evidence to that.

The issues can be that, I want to emphasize, if a child is not emotionally, mentally ready for that, yeah, they get injured. But I'll say this, to me, it's always this weird thought process that parents often have no issues with letting their children play football and basketball, the possibility of getting injured, and potentially breaking bones, in sports, you know, major sports, are much much higher. Resistance training is one of the safest things you can do, in a supervised environment. So, yeah, with children, again, very young, as young as six, seven, eight-years-old, there's been a good compelling research on this that they can do it.

I generally say you want to start off with lighter loads with them. And again, it's getting them into the feel for doing it. And look, when you're dealing with children, the most important thing is making it fun. So, if something is not fun, you're forcing them to do it, not only is it not going to work and you're going to have rebellion against it but it can also later on in life get them to a point where they're kind of adverse to doing that. So, again, I think what's really important is to make it enjoyable for them. And it improves self-esteem, obviously, it improves, you know, bullying in children, these are all things that can help to stave off a lot of the issues that children can have, makes them better athletes. So, from a parent standpoint, you can get scholarships, if that's the avenue they want to pursue, it can make them better in their sports and lead to just a host of positive improvements.